Classification is a process by which plant kingdom is divided into a number of groups or taxon (pl.taxa) such as kingdom, phylum, class, order, family, genus, species on the basis of similarities and dissimilarities between plants.

The necessities of classification are as follows:

There are about five lakhs of species of plants in the world.

1) We will not have to learn about all the plants one by one if we learn about a few plains of different groups according to classification.

2) With short time and less labour, we can study a lot of plants by classification.

3) The knowledge of classification helps us to identify species.

4) The fundamental knowledge of classification is necessary to carry on research work in agriculture, forestry, horticulture, environment, ecology and reproduction

5) To know the mutual relationship among the plants, knowledge of classification is inevitable